TM 9-816 Technical Manual for 4- to 5- Ton 4x4 Tractor Truck (Autocar Model U-7144T) DESCRIPTION a. The 4-to 5-ton 4x4 Tractor Truck (Autocar Model U-7144T) is a cab-over-engine vehicle. Power is furnished by an RXC model Hercules engine. When necessary power can be transmitted to the front wheels through a centrally located transfer case. Hub construction allows the wheels to be mounted dually at both front and rear. A support bracket behind the cab carries two spare tires. A large rectangular tank attached to the frame midway between the wheels on the left side carries fuel. A battery box and two air reservoir tanks are located in a similar position on the right side. b. This tractor truck is manufactured in both open and closed cab-type vehicles.